Unnamed ('Batza Slough')

Occurrence, Inactive

Commodities and mineralogy

Main commodities Ag; Cu; Pb
Ore minerals cerussite; galena; malachite

Geographic location

Quadrangle map, 1:250,000-scale MZ
Quadrangle map, 1:63,360-scale D-5
Latitude 65.8505
Longitude -155.0664
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is at the mouth of what is informally called Batza Slough at its junction with the Koyukuk River. The site is at about the midpoint of the west boundary of section 10, T. 5 N., R. 18 E., Kateel River Meridian. The location is accurate is within 1,000 feet. It corresponds to location 1 of Cobb (1972).

Geologic setting

Geologic description

What is locally called Batza Slough flows along the western foothills of the Isahultila Mountains through an area of Quaternary flood plain, colluvium, alluvium, and terrace deposits (Patton and others, 1977). The stream gradient is about 50 feet per mile. The rocks in the western Isahultila Mountains consists of Cretaceous pillow basalt and andesite flows, andesitic tuff, volcanic conglomerate and breccia, chert , fine-grained cherty tuff; and coquinoidal limestone. The rocks are widely altered to dark green hornfels. Numerous quartz-latite porphyry dikes occur throughout the Sun Mountain area (Miller and Ferrians, 1968). Cretaceous or Tertiary rhyolite tuff, with subordinate vesicular basalt flows, occurs approximately 5 miles to the south in the Takhakhdona Hills (Patton and others, 1977).
Miller and Ferrians (1968) describe a 2-foot-long angular block of altered silicified rock on a cut bank at the mouth of Batza Slough. The rock contained disseminated cerussite, galena, and malachite. A sample contained about 5 percent lead, 0.5 percent copper, and 3 ounces of silver per ton (Miller and Ferrians, 1968; Cobb, 1973; Cobb, 1975). On the basis of those assays, the dikes, and the regional hornfelsing, Miller and Ferrians (1968) postulated that the mineralization is related to a buried hypabyssal pluton.
Geologic map unit (-155.069027968971, 65.8499401949063)
Mineral deposit model Polymetallic replacement? (Cox and Singer, 1986; model 19a); Polymetallic vein? (Cox and Singer, 1986; model 22c).
Mineral deposit model number 19a?, 22c?
Age of mineralization Fossils in limestone interbedded with the andesitic volcanic rocks are of earliest Cretaceous age (Patton and others, 1977). The mineralization is probably Cretaceous or younger.
Alteration of deposit Silicification and hornfelsing.

Production and reserves

Workings or exploration Only reconnaissance geologic mapping and sampling by government geologists.
Indication of production None

Additional comments

This site is the Batza Slough, U.S. BLM MILS location 0020470018 (Oddenino and others, 1995; Interagency Minerals Coordinating Group, 2004).

References